Radiocommunication



Oct. 16, 1928.

E. M. RAVE RADIO COMMUNlCATION Filed 001'.. 28, 1922 Patented Oct. k16, 1928.

UNITED STATES PATENT OFFICE.

ELMER M. RAVE, OF BROOKLYN, NEW YORK, ASSIGN OR 0F ON E-THIRD T0y BEN TON B. HALE, OFIEQAST ORANGE, NEW JERSEY, AND ONE-THIRD TO DAVID H. REID, OF

BROOKLYN, NEW YORK.

. RADIOCOMMUNICATION.

Application lred October 28, 1922. Serial No. 597,508.

This invention relates to radio communication.

An object of the invention is to obviate the necessity for using wire antennae or aerials for the transmission or reception of signals, messages or electrical energy through space.

Another object of the invention is to provide means and method for so proj ectingand modulating a beam of light that it may be utilized as conductor of electricity.

The invention is of particular application in radio communication in which a beam of light is utilized as the aeral or antennae in either transmission or reception, for conducting high or radio frequency electrical oscillations. f

IVhile it has been suggested (U. S. Patent 1,309,031) to utilize a beam of ionized air or atmosphere as an aerial, the air being ionized by the ultra violet yrays of a pro- `iected beam of light, inthe present invention I do not depend for results on such anunstable ionized gaseous medium which is subject to every breeze and other atmospheric disturbance, and which is electrically conductively unstable or variable. y

It is my present theory (to which I do not desire to be bound however) that by the apparatus shown in the drawing, and by the method hereinafter described, I am able to effect such change in the characteristic of a beam of light as to render the light itself as distinguished from ionized atmosphere) conducting, or as I will' call'it modulated,l

although there'may be slight ionization of the air itselfin the neighbourhood of the projected beam. Any gaseous ionization if it exists, due to my apparatus, does not appear to be important. Throughoutthe following specification yand in the claims I will therefore refer to the beam o'flight,'as herein modified as a .modulated beam of light. By light is meant, not only those ra s that affect the eye and Vare visible, but a so the invisible rays including the infra red, and those visible raysthat are nearthered end of the spectrum and which have longer Wave lengths and are not photoelectric, that is, do not cause appreciable ionization of the atmosphere like the ultra violet rays do. i

I have discovered that, if the light ray or beam has the required characteristics as regarde color and polarization, as .hereinafter cellent results Were obtained when the ionizing ultra violet rays were screened out and when the red or infra red in the ray predominated.

In the present invention the light generated or projected or formed is passed through a pair of flat plates of Iceland spar separated by an air space, which arrangement assures a practical operation of the apparatus kand se-y cures operative results. The propertiesof Iceland spar are now well known. Its most characteristicproperty is that it polarizes light. Light is also polarized when an ordinary ray falls upon a? reflecting surface arranged at an f angle or at the polarizing angle for maximum polarization. Apparently my apparatus po-k larizes the light beam or ray, thereby modifying the characteristics or properties of the beam, making it conducting or modulating it.

Again it is to be understood that I do not desire to be bound or limited by any theories of polarization, the invention residing in the apparatus and method herein illustrated'and hereinafter more fully described, such theory being 4propounded merely to make the inventiondclearer and easier toV grasp and understan l/Vhile I have obtained excellent'iesults with the spaced plates of Iceland spar which, it is believed, cause the formation of the ordinary ray and extraordinary ray plane polarized at right angles to each other, yet I do not desire to ,be limited to the use of this instrumentality for the purpose Aof polarizing. the'lightray and any equivalent operative instrumentality may be employed, such for instance, as a Nicols prism or a reecting surface .arranged at the lpolarizing angle.

To reduce the cost of installing and maintaining the towers or antennae as now used I utilize a beam of light having the character- Cl f) `comprises three elements (1) istics above described to conduct and project or radiate the electrical oscillations as ether waves or to receive such waves, the oscillations being superimposed. upon or directed by the modulated beam.

The problem involves the utilization of a conducting medium which is not apprcciably affected by atmospheric conditions` or by the sun or other sources et light, the latter causing the ionization of the air or atmosphere by reason of their ultra violet rays, and which may be regulated to properly control the electric oscillations and maintain them.

To obtain the desired results my apparatus a source of' light, (2) a polariaer, as I call it, and means, such as a metal screen, for imposing and receiving thehelectrical oscillations upon and from, respectively the polarized or inodulated beam and forming a` terminal of a local circuit connecting the beam thereto.

The source of light should be adjustable to vary the intensity of the beam according to conditions and to vary thelength oli the beam and its capability for directing or carrying or radiating and receiving the electrical oscillations.

The screen should be such as not to obstruct the beam and is adj ustablewith reference to the polarizer to vary its posit-ions in the beam and thereby vary the results obtained, i. e. the distance to which radiation takes place.

It is a matter of everyday experience that rays of light cross each other without interference,A the rays however, will be absorbed more or less in the atmosphere depending upon the intensity of the source and upon the nature of the light, that is, upon its wave length. I lin-d from actual observation and experiment that in the use of my apparatus the presence of other beams of light docsA not influence my projected beam and the electrical oscillations associated therewith.

The degree of modulation of the beam of light or its effectiveness can be controlled either by adjusting the polarizer or the screenV or terminal, or both, or wave length, that is the color of the relative quantity of long waves (the waves near the red end or below it) in the beam or any or all. For adjusting the polarizer the plates are so mounted as to be capable of movement towards and away from each other. The adjustment must be delicately controlled as the effectiveness of the beam, which is adjustable, will depend on meteorological conditions, such as whether it is day or night. The beam must be insulated from the earth and surrounding objects.. j

The actual source of light may be an ordinary electric bulb or a bulb` of the concentrated filament type or an arc. In order to get the best results parabolic reflectors may be employed to concentrate they rays and direct them in the desired directions. The rcflectors may be made of Zinc or silver, as such materials will absorb no more than two or three per cent oil the rays, the remainder being reflected. The infra red rays when their use is desirable, may beinereased to a marked extent 'by adding barium chloride to the are electrodes.. At a temperature (at the electrodes) of 34600 C., the energy output has been calculated to be between 15 and 2O kilowatts.

It is to be understood that two or more beams may be utilized in a. given installation or system, forinstance on an airplane where a second beam is used as a. counterpoise.

With this apparatus radio communicationv in space either transmission or reception'between stations wherever located, whether up in the air, under the water, under the ground or on the ground or water, is possible. V

In the accompanying drawing I have illustrated one embodiment of theinvention" in which Figure 1 is a side elevation of the apparatus.

Figure 2 is an end view, parts beingv omitted. Figure 3 is a vertical sectional View, and Figure 4l is a Viewv of a Nicols prism. Y Apparatus embodying the present invention comprises a projector 1, which resembles an ordinarysearchlight, and consists of a cy-` lindrieal shell 2, closed at one end 3, and open at the opposite end 4., from` which the beam of light is projected. The shell'2 comprises an outer-part 2aM of metal, lined with insulation 2", whereby the beam and electrical circuits are thor-oughly insulated from thel ground and surrounding obj ects.Y

At the rear of the projector 1, is the source of light 5, which in the embodiment disclosed comprises two electrodes 6, arranged at right angles to each other and forming a gap .7 between them, across which the are is formed, causing light. The electrodes G are mounted in the shell 2 as indicated at 8 and are preferably adjust-able relatively to each other to. vary or adjust the are (by means not illustrated). The electrodes 6 may bemade of y any suitable material, for inst-ance, carbon rods. Metal vanes 9 may be placed upon the electrodes or upon their mountings to radiate heat and for cooling purposes. Access may `be made to the interior of 'the shell 2 to adjust or remove the electrodes 6 through a door 10, having afwindow 11 therein.

Behind the electrodes 6 within the projector 1, is placed comprises a central reflecting surface 12a. and reflecting surfaces 12b, arranged around the edges of the surface 1.2a which reflect and direct the light from the are forwardly through opening l projecting it into space. rIhe reflectors 12b are adjustably mounted in the end 3 of shell .2 (as indicated at 13) being movable in and out by handles 14.

a parabolic reflector 12, whichV Mounted within the projector 1 between the source 5, of light, and the end 4 of the proj ector is a pair ot' transversely arranged parallel plates 15, a of a light polarizing material such as Iceland spar. These plates 15, 15 are spaced from each other forming an air space 16 between them, For convenience I will call the spaced plates 15, 15a, a. polarizer. In lieu of the plates 15, 15, illustrated in Fig. 3, I may substitute a prism of the character illustrated in Fig. 4 which is an ordinary Nicols prism comprisinga piece of Iceland spar 17 cut on an inclined aXis 17l and cemented together by a thin film of Canadian balsa-m. A Nicols prism polarizes light but reiiects the ordinary ray allowing the extraordinary ray only to pass through, the latter ray being plane polarized.

The plate 1521 is preferably mounted in the projector 1, for movement towards and away from plate 15, while maintaining the parallelism, varying the thickness of the air space 16, between them. The means for moving plate 15a comprises racks 18 secured to opposite sides of the plate 15a and suitably guided in guideways 19 in projector 1. The racks 18'areactuated by pinions 20 which may be manually rotated bythe knobs 21 eX- teriorly arranged upon opposite sides of the projector 1. (The racks 18 may be actuated yby a single knob connected tothe pinions 20,

if so desired.) rlhe arrangement of racks and pinions disclosed however, is a goodL one for quickly and accurately adjusting the plates 15, 15a relatively to each other and at the same time for preventing the tilting orV binding of the movable plate on the inner sides ot' the projector' l.

One surface 22 of the plate 151 is coated with a suitable material, such as a red vegetable coloring material, which will screen or cut off the ultra violet rays and prevent their projection into space in the beam but which willallow the longer waves near .the red end of the spectrum andthe infra red rays to pass through and form the beam.

In front of the polarizer 15, 15a within the projector 1 in the path of the beam is mounted a transversely arranged terminal 23 forming part of a local circuit including sliding contacts 24 on the terminal 23 and projector respectively (to allow their relative adjustment while maintaining the circuit) and the insulated binding post 25 on the outside of.

the projector 1 connected to the contacts 24. rI'his local circuit (which is not illustrated in detail) may comprise any circuit and its adjuncts which is adapted to form or does form part of transmitter orreceiver. l

The terminal 23 is ofsuch a character that it does not obstruct the `passage Vof the ray or beam or shut it oil materially. For this purpose where alternating current is used, a metal screening or gauze 26 embedded in glass 27 has been found satisfactory, the

glass allowing the light to pass through and the screening allowing it also by reason of its porous or perforate character, they terminal having however a maximum amount of surface in contactwith the light beam, whereby the electrical oscillations or alternating current may be readily conveyed from one lto the other, to and froml binding post 25.

The glass forms a rigid support for the terminal screen and thoroughly insulates it from the projector and surrounding objects but does not prevent the transfer of the oscillations from and to the terminal to and from the beam.` j

The terminal 23 is mounted parallel to the plates 15, 15a and is adjustable towards and away from such plates (While maintaining the parallelism) to. vary its position -in the beam. For thispurpose a air of racks 28 are secured to the frameworli) of the terminal 23 at the opposite sides and are vsuitably guided in the ways 19 in the projector 1. Pinions 30 engage the vracks and are operated i'rom the outside of the projector'l by the knobs 31, this actuating mechanism being similar to that for moving or adjusting the plate 15a. It should be understood that the terminal 23 may be located at any point in the beam even be ond the end 4 ofl the projector l and is on y mounted inthe projectorfor convenience.

The arc chamber 32 formed between the end 3 of the projector and plate 15 is provided with openings'33 through the projector `1v to allow a good circulation vof air, keeping the `chamber 32cool and preventing ionizationV of the gases therein and for quickly diffusing such ionized gases.4 In like manner the chamber 32EL formed between the plate 15a and terminal 23 is provided with openings'34 to keep the air therein cool, to prevent its ionization and to rapidly difusesuch ionized air.

The projector 1 is mounted for universal movement upon a base 35, which is 'of insulating material thoroughly insulating the apparatus from ground. For this purpose/the projector is mounted upon trunions 36 upon a table 37, in turn rotatable on a vertical axis 38 upon base 35, whereby the projector may be swung vertically and laterally respectively. This mounting allows the beam forming the aerial to be projected vertically, upwardly in all directions at any inclination, horizontally in all directions or downwardly at dit,-

k)ferent angles in all directions according to the requirements or to the location of the projector in space, whether below the surface of the ground or water, up in the air, or on the surface of the ground or water.

The intensity `of the beam and its length `can be adjusted by varying the amount of power (electrical) .applied tothe arc electrodes (means for doing this is not illustrated, as such meansare well known). vIn any given apparatus embodying this invention, I nd not only the `power cillations but also the `arc vcan be materially reduced.

Ymanner by the adjustment .the intensity of the received oscillations when acting as a receiver. VHence it is possible to adjust either the power applied'to the arc 5, or .the power of the electrical oscillations being impressed upon thebeamor thecondition of the beam (as regards modulation) vor any or all in order to transmit most economically. When it-isldesired to transmit short distances behind the-,electrical ospower applied tothe The adjustment of the polarizer, I iind, enables me to secure optimum conditions of the .beam for optimum transmission or reception for each Wave length used. transmitting or receiving it is preferable to tune the local circuit to thedesired wave length in the usual ot the inductances and capacities ofthe circuit and also to adjust .thepolarizer (plates l5, a) and the position of the terminal 23 until/the optimum or maar vmum signal is heard either in thelocal telephones When the device isbeing used as a receiver, or as indicated vby suitable transmitting indicating devices or instruments, such as a thermocouple or hotwire type ammeter, when used as a transmitter.

While I do not know the ultimate causes of the results obtained -by the adjustment of the polarizer (the relative Vmovement ot Ithe plates 15, 15a) and I donot Wish to be bound by the theory of operation proposed, yet I believe that the results obtained 4by such adjustment vary the degree `or nature of the polarization of the light ray orbeam and the amount of or character ot modulationofthe ray which must be adjusted according .to

varying atmospheric or meteorological conditions due, Jfor instance, to sunlight and the resulting ionization of the air around Athe `beam due to thesunliglit. In other words this adjustment enables the beam to etliciently carry and radiate and receive electrical oscillations of different wave lengths under dit- Jferent atmospheric conditions.

The adjustment of the terminal 23 along the beam varies beam and hence adjusts the beam-tor effectively transmitting orreceiving oscillations of different Wave lengths. Irrespective of the ultimate reasons or theories of operation of these adjustable devices, I iind that by adjusting either one orthe other, or both ot' them the apparatus may be adjusted to send vor receive amaximum optimum signal observable inthe telephones or indicating or measuring instruments. `In other y words theseveral de the effective length of .the

vices must -be adjusted until optimum results are obtained, as noted in the telephone ear pieces or by such me suring or indicating instruments. Y A

In the use of the apparatus the 4beam of light yis generated or formed and directed inV` to space with the required intensity as above explained. It is then passed through the polarizing plates l5, l5fl these plates being adjustable as above described. Such a-beam is electrically conductive, especially of radio frequency oscillations, and such oscillations are then impressed uponthc beam or directed along the path 4ot the beam, either through terminal 28 in transmitting or by the action of the electromagnetic waves in space, when receiving, which are ztransferred through the the terminal 23 to the receiver, the terminal 23 being adjustable. i

I claimz l l. The hereindescribed method Whichcom sists in forming a beam ot light, polarizing said beam, projecting` it into space, and conducting electricity along saidfbeain.

2. The hereindescribedmethod whichjconsists in forming a ray of light in which `the waves at the infra red end of the spectrum predominate, polarizing said ray and imposing electrical'oscillations upon said ray.`

Radio apparatus comprising means :for forming a light ray, a polarizer in `the kpath or the ray and a terminal arranged in the path of the ray for connecting said ray in van electric circuit.

4L. :Radio apparatus comprising means tor generating a light ray, spaced plates of light polarizing material arranged in the path of the ray, and a-terminal arranged in the path of the ray in lront of said plates for connecting said ray in an electric circuit, such terminal being of a 'form which will allow ot fthe passage therethrough ot' the ray of light.

5. Radio apparatus comprising means for generating light and proj ecting it as a beam, a polarizcr v arranged in the path of said beam and comprising relatively movable plates, means for umoving said plates towards and away from each other' and a `circuit comprising aterminal arranged in the path of said beam in ifront of said polarizer and inov-' able along said beam to position it atr differ ent points, such terminal being'v of a form Which will allow of the passage therethrough of the beam otlight.l

6. Radio apparatus comprising I an insulated projector ,havingan arc chamber and means for Ventilating it, spaced plates of Iceland spar arranged `in said projector transversely lot the projected beam ot flight, a glass embedded metal I*terminal arranged transversely of the beam Ain front of said plates and adapted to be'connected to a circuit, such terminal'being ot a form which will allow of the passage therethrough of thebeam 'of light, and means :tor causing 4un y to be of substantially one Wave-length light.

7 Radio apparatus comprising an insulated projector having a source of light and means for reflecting it forwardly in the form of a beam, a polarizer in the path ofthe beam and comprising spaced plates of Iceland spar one of which is treated to prevent the projection of the ultra Violet rays, a glass embedded metal terminal arranged in the path of said beam in front of said polarizer and adapted to be connected in a circuit, such terminal being of a form which will allow of the passage therethrough of the beam of light and means for adjusting said polarizer and said terminal. f

In testimony whereof I aX my signature,

ELMER M. RAVE. 

